Fluid control safety system

ABSTRACT

A FLUID CONTROL SYSTEM UTILIZED IN CONJUNCTION WITH A PAIR OF MANUALLY OPERATED FLUID VALVES SO SPACED AS TO NECESSITATE THE USE OF BOTH HANDS BY AN OPERATOR FOR CAUSING ACTUATION OF A FLUID MOTOR, SUCH AS A HYDRAULIC PRESS. THE TWO MANUALLY OPERATED VALVES SELECTIVELY APPLY PRESSURIZED FLUID TO A PAIR OF FLUID LINES WHICH ARE CONNECTED TO A MAIN FLOW VALVE AND A PAIR OF CONTROL VALVES. THE CONTROL VALVES ARE CONNECTED THROUGH A PRESSURE STORAGE NETWORK TO THE MAIN FLOW VALVE FOR PREVENTING ACTUATION OF THE MAIN FLOW VALVE IN THE EVENT THAT BOTH OF THE MANUALLY OPERABLE VALVES ARE NOT ACTUATED WITHIN A PRESET TIME INTERVAL.

p 1971 o. PHILBRICK I 3,605,554

FLUID CONTROL SAFETY SYSTEM Filed March 5, 1970 I ""1 i i I I I L I N l9 l l L J o v |NVEN.TOF\:, w Danlel Phllbl'lCk BYM'yW'm ATTORNEY UnitedStates Patent US. CI. 91-38 Claims ABSTRACT OF THE DISCLOSURE A fluidcontrol system utilized in conjunction with a pair of manually operatedfluid valves so spaced as to necessitate the use of both hands by anoperator for causing actuation of a fluid motor, such as a hydraulicpress. The two manually operated 'valves selectively apply pressurizedfluid to a pair of fluid lines which are connected to a main flow valveand a pair of control valves. The .control valves are connected througha pressure storage network to the main flow valve for preventingactuation of the main flow valve in the event that both of the manuallyoperable valves are not actuated within a preset time interval.

BACKGROUND OF THE INVENTION Field of the invention The present inventionrelates generally to safety apparatus for manually operated fluidcontrol systems, and more particularly, to a new and improved fluidcontrol safety system necessitating substantially simultaneous actuationof a pair of input devices to produce system actuation.

Description of the prior art Hydraulic machinery, capable of exertingrelatively large forces within a confined area, have been in extensiveuse for a number of years. In many cases, such machines are utilized toperform a mechanical operation on a relatively small workpiece which istypically inserted into the machine by an operator who thereafterremoves his hands from the proximate area of the workpiece and thenactuates the machine as by a manually operated lever. Very often, inorder to increase his output, an operator may employ one hand to insertthe workpiece into the machine and his other hand to operate theactuating lever. Such actions are inherently dangerous and often resultin serious injury to the operators hands.

The prior art is generally cognizant of the above-mentioned problem andhas offered numerous solutions conventionally taking the form of a pairof serially connected manually operated valves which are spaced fromeach other so as to require the use of both hands of the operator inorder to actuate the particular fluid motor being employed. Furthermore,various more complex systems have refined the serially connected valvecontrol arrangement so that both manual valves must be operated nearlysimultaneously such that the operator is precluded from permanentlytying down one of the valves to permit one hand operation.

While such prior art control systems have generally served the purpose,they have not proved satisfactory under all conditions of operation fora number of reasons, one of which is that they are often highly complex.This factor not only increases the initial cost of the apparatus, butinherently increases maintenance outlays while substantially reducingoverall system reliability.

SUMMARY OF THE INVENTION The present invention is summarized in that afluid control safety system for a fluid motor includes an inlet adaptedto communicate with a source of pressurized 3,605,554 Patented Sept. 20,1971 operated valve having a second port and being locked in the offposition in response to fluid pressure at the second port; a controlassembly communicating with the pair of manually operated valves and thesecond port for applying a fluid pressure to the second port ofpredetermined time delay after operation of either of the pair ofmanually operated valves whereby the pressure operated relay is lockedin the off position; and a feedback assembly communicating with theoutlet port of the pressure operated relay and the control means andcooperating with the control means to block the application of fluidpressure to the second port in response to fluid pressure at the outletport whereby the feedback assembly assures actuation of the fluid motorin response to substantially simultaneous operation of the pair ofmanually operated valves.

It is an object of the present invention to construct a fluid controlsafety system utilizing fewer components than the number of componentsheretofore required.

The present invention has an additional object in that a pair of spacedmanually operated valves must be operated within a preselected timeinterval in order to provide an output pressure signal and that bothvalves must thereafter be released prior to the initiation of asubsequent operation.

'It is a further object of the present invention to construct a fluidcontrol safety system utilizing three fluidic diverting relays and adelayed action storage device.

The present invention is advantageous over conventional fluid controlsafety systems in that it is relatively simple in construction and isreadily adaptable to inexpensive fabrication techniques.

Other objects and advantages of the present invention will be more fullyapparent from the following description of a preferred embodiment whentaken in conjunction with the accompanynig drawing.

BRIEF DESCRIPTION OF THE DRAWING The figure is a schematic diagram of afluid motor energizing network embodying a fluid control safety sys temaccording to the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawing, thefluid control safety system of the present invention is embodied in anenergizing network for a fluid motor which may be of any suitable typesuch as a hydraulic cylinder 10. Hydraulic cylinder 10 has an outputshaft 12 adapted to be axially moved by a piston 14 which is biased by aspring 16 such that shaft 12 is normally retracted within the cylinder.A port 18 in a wall of the cylinder 10 communicates with the interior ofthe cylinder so as to permit hydraulic fluid under pressure to act uponpiston 14 and cause the movement of shaft 12 for operating any suitablemachine such as a hydraulic press (not shown). Port 18 is connected by aconduit 20 to a common port 22 of a fluidic diverting relay 24.Diverting relay 24 may be of any suitable construction and isschematically illustrated as including a first valving block 26 havingan internal passage 28 establishing communication between ports 22 and30, and a second valving block 32 having an internal passage 34establishing communication between ports 22 and 36. The two valvingblocks 26 and 32 are normally biased by coil spring 38 to positionswherein port 30 is normally open and port 36 is normally closed, withport 22 designated as a common port. The relay 24 is moved from itsnormal position to an actuated position by any suitable means, such as apiston and/ or diaphragm in an actuating chamber 40 which has a port 42communicating with a pneumatic pressure line 44. Fluid for the hydrauliccylinder 10 is obtained from a fluid reservoir or sump 46 through asuction line 48 and a fluid pump 50 which communicates with port 36 ofrelay 24 through a pressure line 52. This fluid discharges from thecylinder 10 through port 30 and a suitable conduit 54 back to sump 50 toform a closed fluidic circuit.

Pressurized air for actuating the diverting relay 24 is supplied by acommon air pressure source 60 which is connected by branched conduits 62and 64 to manually operated valves 68 and 69, respectively. Each valveincludes a pair of valving blocks 70-71 and 72-73 which are connected atone end to a two-position manually operated pushbutton 74-75 and attheir other end to a biasing spring 76-77. Each valving block has a pairof internal passages therethrough, so arranged that the passages of oneor the other of the valving blocks are in register with inlet ports78-79 and 80-81 and outlet ports 82-83 and 84-85 for each of the twopositions of the pushbutton 74-75. Thus, in an unactuated or staticstate, wherein pushbutton 74-75 is not depressed, biasing spring 76-77moves valving blocks 70-71 and 72-73 to positions such that the crossedinternal channels are operative to interconnect port 78-79 with port84-85, and to interconnect port 82-83 with port 80-81. Similarly, whenpushbutton 74-75 is depressed, the valving blocks are moved to theiractuated positions wherein port 78-79 is interconnected with port 82-83,and port 80-81 is interconnected with port 84-85.

input ports 78 and 79 of valves 68 and 69 are respectively connected tobranched conduits 62 and 64, while ports 80 and 81 are adapted toprovide selective venting for the system. Furthermore, outlet ports 84and 85 are closed by plugs 86 and 87, respectively, while ports 82 and83 are connected to respective input conduits 88 and 89 which feedpressurized air to the fluid control safety system of the presentinvention, indicated generally at 100.

Fluid control safety system 100 includes three fluid diverting relays110, 130 and 150 which may be of any suitable construction and may beidentical to each other. Each relay is schematically shown as includinga first valving block 111-131-151 having an internal passage 112-132-152establishing communication between ports 113 and 114, 133 and 134, and153 and 154, respectively, and a second valving block 115-135-155 havingan internal passage 116-136-156 establishing communication between ports113 and 117, 133 and 137, and 153 and 157, respectively. The two valvingblocks are normally biased by coil spring 118-138-158 to positionswherein port 114-134-154 is normally open and port 117-137- 157 isnormally closed, with port 113-133-153 designated as a common port. Eachof the relays 110, 130 and 150 is moved from its normal position to anactuated position by any suitable means, such as a piston and/ordiaphragm operator in an actuating chamber 119-139-159 which has a port120-140-160. In addition, each of the relays may be locked or inhibitedfrom actuation by any suitable means, such as a piston and or diaphragmoperator in an inhibit chamber 121-141-161 which cooperates with biasingspring 118-138-158 to increase the force exerted thereby to a levelsufiiciently large to prevent the valving blocks from being moved totheir actuating position by fluid pressure at actuating chamber 119-139-159. Fluid pressure may be placed in communication with inhibitchambers 121, 141 and 161 through ports 122, 142 and 162, respectively,so as to permit selective locking of the relays, as will be explainedbelow.

Referring to the details of the fluid circuit of the presentinventin,'input conduit 88 is connected to port 120 of relay as well asto ports 160 and 157 of relay 150, while input conduit 89 is connectedto port 134 of relay and port 117 of relay 110. Pressure line 44 issimilarly connected to common port 113 of main relay 110 and a feedbackconduit 170 which establishes communication between common port 113 andport 162 of relay 150 and port of relay 130. Relays 130 and areinterconnected at their respective ports 133 and 154 by a fluid line 172so as to provide a fluid flow path there between.

The control system 100 further includes a flow restrictor 174 and aone-way valve 176 which are connected in parallel relationship betweenport 153 of relay 150 and a pressure storage tank or accumulator 178.The one-way valve 176 is oriented such that its outlet communicates withrelay 150 to provide an unrestricted flow path around the flowrestrictor 174 in the direction indicated by the arrow. The pressurestorage tank 178 is connected with inhibit chamber 121 of main relay 110through conduit 180 and port 122 to complete the fluid circuit of thecontrol system 100.

In operation, manually operated pneumatic valves 68 and 69 are locatedin spaced relationship with each other such that an operator is requiredto utilize both hands in order to simultaneously depress the two valvesfor energizing the system from its standby or unactuated state. In thestandbystate, air pressure supply 60 is isolated from control system 100by valves 6-8 and 69 which respectively direct the pressurized airthrough inlet ports 78 and 79 to outlet ports 84 and 85 where fluid flowis blocked by plugs 86 and 87. At this same time, input conduits 88 and89 are vented through exhaust ports 82 and 80 of valve 68 and ports 83and 81 of valve 69, respectively. Therefore, input conduit 88 isnormally unpressurized, and a fluid pressure signal does not appearWithin actuating chamber 119 of the pressure operated valve or divertingrelay 110. Consequently, relay 110 assumes its off or static positionand the input conduit 89 is blocked at normally closed port 117 toprevent fluid pressure from appearing in output pressure conduit 44. Asa result, actuating chamber 40 of hydraulic diverting relay 24 receivesno fluid pressure such that the relay 24 also remains in its normallyoff position permitting the venting of hydraulic cylinder 10 through therelay to the hydraulic fluid reservoir 46. The biasing spring 16 thusacts against piston 14 to retract output shaft 12 and dischargehydraulic fluid from Within the cylinder to the reservoir 46.

When operation of the hydraulic cylinder is desired, manually operatedvalves 68 and 69 are simultaneously actuated by the operator therebyplacing air pressure supply 60 in communication with input conduits 88and 89. Pressurized fluid is thereafter fed through input conduit 88 andport 120 to the actuating chamber of diverting relay 110 causing therelay to move to its on position such that normally closed port 117 isopened and is placed in communication with outlet port 113 throughinternal pas sage 116. Pressurized fluid is then fed from input conduit89 through relay 110 to the output conduit 44 and thence to theactuating chamber 40 of the hydraulic diverting relay 24 at port 42causing movement of the relay to its on position. When valve 24 isactuated, a hydraulic fluid flow path is established from reservoir 46through conduit 48, hydraulic pump 50, pressure line '52, port 36,internal passage 34 0f the diverting relay 24, port 22, hydraulicconduit 20 and port 18 to the hydraulic cylinder 10. In this manner,pressurized hydraulic fluid is fed from pump 50 to the interior of thehydraulic cylinder 10 to move piston 14 downwardly against the biasingforce of spring 16 causing axial movement of output shaft 12 whichresults in the operation of the hydraulic press (not shown).

At this same time, the pressurized fluid appearing in output conduit 44is applied by feedback conduit to the actuating chamber 139 of controlrelay 130 as well as to the inhibit chamber 161 of control relay 150.This causes actuation of relay 130 to its on position to block inletport 134 and prevent the flow of pressurized fluid from input conduit 89to fluid conduit 172. In addition, the fluid pressure at inhibit chamber161 prevents actuation of control relay 150 by the fluid pressure whichis applied through port 160 from input conduit 88; pressurized fluid inconduit 88 is thus blocked at inlet port 157 from communicating withoutlet port 153 of diverting relay 150.

Since the control valve 130 is actuated by the fluid pressure withinfeedback conduit 170, fluid is precluded from flowing from input conduit89 to the flow restrictor 174. Similarly, since the fluid pressure atinhibit chamber 161 prevents actuation of control relay 150, pressurizedfluid cannot flow from input conduit 88 through ports 157 and 153 ofrelay 150 to the flow restrictor 174. In this manner, fluid pressure isprevented from building up within pressure storage tank 178 such that nopressure is applied through port 122 to the inhibit chamber 121 of themain diverting relay 110. Thus, the fluid pressure within feedbackconduit 170 both actuates control relay 130 and inhibits actuation ofcontrol relay 150 so as to isolate inhibit chamber 121 of valve 110 fromthe incoming pressurized fluid. This permits main valve 110 to remainactuated for pressurizing output conduit 44 and producing energizationof hydraulic cylinder 10.

When energization of hydraulic cylinder is no longer desired, bothvalves 68 and 69 must be released to block the flow of pressurized fluidto input conduits 88 and 89 and vent the system. This removes fluidpressure from the actuating chamber 120 of main diverting relay 110 suchthat the relay drops back to its normally off position to block inletport 117 and permit venting of output conduit 44 through internalpassage 112 and ports 113 and 114. In this manner, pressurized fluid isremoved from actuating chamber 40 of the hydraulic relay 24 blocking theflow of high pressure hydraulic fluid to the hydraulic cylinder 10 andsimultaneously placing the hydraulic cylinder in communication withdischarge conduit 54 to allow piston 14, and consequently shaft 12, tomove upwardly under the biasing force exerted by spring 16. The systemis thus placed in its standby state, as defined above.

The fluid control safety system 100 cooperates with the two manuallyoperated valves 68 and 69 such that operation of the hydraulic cylinder10 is produced only upon substantially simultaneous operation of bothmanually operated valves as described above. As can be seen in thedrawing, if the operator attempts to cause operation of the hydrauliccylinder 10 by depressing only valve 68, pressurized fluid will besupplied to input conduit 88 and will cause actuation of the maindiverting relay 110; however, input conduit 89 will not be pressurizedand no fluid will flow through the relay to output conduit 44.Similarly, if the operator attempts to energize the hydraulic cylinder10 by operating pneumatic valve 69 alone, input conduit 88 will not bepressurized so that no fluid pressure will be applied to the maindiverting relay 110 at port 120; thus, the pressurized fluid withininput conduit 89 will be isolated from output conduit 44 by closed port117.

As explained above, operation of only one of the two manually operatedvalves 68 and 69 will not produce energization of the hydraulic cylinder10. In addition, and in order to prevent the attainment of one-handoperation of the fluid control system of the present invention bypermanently tying down one of the two manually operated valves, controlrelays 130 and 150 cooperate with flow restrictor 174, pressure storagetank 178, and feedback conduit 170 to preclude the actuation of the maindiverting relay 110 in the event that both of the manually operatedvalves 68 and 69 are not depressed within a preselected time interval.

Referring more specifically to the operation of the system when anoperator attempts to avoid two-hand operation, if manually operablevalve 68 is tied down, pressurized fluid will appear at input conduit 88and will be fed to actuating chamber 119 of the main diverting relay aswell as to the actuating chamber 159 and normally closed port 157 ofcontrol relay 150. As a result, the main diverting relay 110 will becomemomentarily actuated; however, since no pressurized fluid is fed toinlet port 117 from input conduit 89, no fluid pressure will appearwithin output conduit 44 or feedback conduit 170. Since pressurizedfluid is not fed to feedback conduit 170, the inhibit chamber 161 ofcontrol relay 150 will not receive a fluid pressure signal thuspermitting actuation thereof in response to the pressurized fluid fed toits actuating chamber 159. Since port 157 of control relay 150 isconnected to input conduit 88, pressurized fluid will thereafter flowthrough port 157, internal passage 156 and port 153 to the flowrestrictor 174 and thence to the fluid pressure storage tank 178'. Inthis manner, fluid pressure will build up within tank 178 at a ratedetermined by the flow rate setting of restrictor 174 and will beapplied through conduit 180 to the inhibit chamber 121 of main divertingrelay 110. The application of sufficient pressurized fluid to theinhibit chamber 121 causes diverting relay 110 to drop back to itsnormally off position, assuring isolation of pressure line 44 fromincoming fluid pressure.

Thus, with the manually operated valve 68 tied down, the diverting relay150 is actuated causing the pressurization of storage tank 178 and thelocking-out of main diverting relay 110 by pressure applied to itsinhibit chamber 121. If the operator thereafter attempts to initiateactuation of hydraulic cylinder 10 by depressing manually operated valve69, the pressurized fluid in input conduit 89 will be precluded frompassing through main relay 110 at the normally blocked port 117 suchthat output conduit 44 is prevented from becoming pressurized. Sincefeedback conduit 170 is in communication with output conduit 44, nofluid pressure will be fed back to the inhibit chamber 161 of divertingrelay 150 thereby allowing the diverting relay 150 to remain in itsactuated position to maintain the pressurization of storage tank 178.

In order to reset the system, it is necessary to release a manuallyoperated valve 68 for removing fluid pressure from actuating chamber 159of the diverting relay 150 which thereafter reverts to its normally offposition. The release of relay 150 establishes a venting path for thepressure storage tank 178 through oneway valve 176, port 153, internalpassage 152 of control relay 150, port 154, fluid line 172, port 133,internal passage 133 of control relay 130, port 134, input conduit 89,and ports 83 and 81 of manually operated valve 69. The one-way valve 176thus by-passes flow restrictor 174 and rapidly releases the pressurewithin the storage tank 178 permitting the system to once again assumeits standby condition for subsequent normal operation.

A similar lock-out condition is produced if the operator attempts toavoid two-hand operation by tying down manually operated valve 69. Undersuch conditions, input conduit 89 will become pressurized so as to applyfluid pressure to inlet port 117 of diverting relay 110. Since no fluidpressure signal is applied to the actuating chamber 119 thereof,diverting relay 110 remains in its normally off position such thatpressurized fluid is precluded from flowing to outlet conduit 44 as wellas to the feedback conduit 170. For this reason, actuating chamber 139of the control relay receives no pressurized fluid and remains off.Similarly, since the control relay receives no actuating pressure signalat its actuating chamber 159, it also remains off so that both relayscooperate to provide a serial flow path to feed pressurized fluid frominput conduit 89 to the flow restrictor 174 and thence to the pressurestorage tank 178. As before, the pressure built up within tank 178communicates with the inhibit chamber 121 of main diverting relay 110through port 122 to prevent subsequent actuation thereof.

With manually operated valve 69 tied down, and a sufficient pressurebuilt up within storage tank 178, sub- 7 sequent operation of manuallyoperated valve 68, while causing a pressure input signal to appear atthe actuating chamber 119 of the main diverting relay 110, will notcause actuation thereof due to the fluid pressure existing withininhibit chamber 121. The fluid control safety system of the presentinvention is thus locked-out once again and can only be recycled to itsstandby condition by releasing manually operated valve 69 so as toprovide a discharge or venting path for the pressure tank 178 throughone-Way valve 176, control relays 150 and 130, and ports 83 and 81 ofvalve 69. Upon release of the pressure within the storage tank 178, andthe resultant removal of fluid pressure at inhibit chamber 121 of themain diverting relay 110, the system is reset for subsequentenergization.

Thus, it can be easily seen that a fluid pressure output signal willonly be produced Within outlet conduit 44 if both manually operatedvalves 68 and 69 are operated within the preselected time interval setby the flow rate setting of restrictor 174, during which a sufficientpressure is being built up within storage tank 178 to inhibit orlock-out the main relay 110. In other words, main valve 110 will beinhibited from actuation by fluid pressure stored in tank 178 unlessboth manually operated valves 68 and 69 are operated within the timedelay required for such inhibit pressure to be built up with the storagetank. As described above, actuation of both valves 68 and 69 blocks theflow of pressurized fluid to the storage tank and will prevent alock-out of main valve 110 if they are both operated Within theaforementioned time interval.

In this manner, while the fluid control safety system of the presentinvention is simple in construction, its operation assures the safety ofthe operator by necessitating the use of both hands to cause movement ofthe particular machine being controlled. It should also be noted, thatthe present invention permits the use of identical diverting relays soas to reduce both the complexity and cost of manufacture of the overallsystem. While the present fluid control system has been described hereinas a pneumatic system, similar operation can be obtained through the useof hydraulic fluid rather than pressurized air in accordance with thegeneral principles of operation of the present invention.

Inasmuch as the present invention is subject to many variations,modifications and changes in detail, it is intended that all mattercontained in the foregoing description or shown in the accompanyingdrawing shall be interpreted as illustrative and not in a limitingsense.

What is claimed is:

1. A fluid control safety system for a fluid motor comprising,

inlet means adapted to communicate with a source of pressurized fluid;

a pair of manually operated valves communicating with said inlet means;

a pressure operated relay communicating with said pair of manuallyoperated valves and having an outlet port communicating with the fluidmotor, said pressure operated relay having a normally oif position andbeing actuated to an on position in response to pressurized fluid fromboth of said pair of manually operated valves to apply pressurized fluidto the fluid motor;

said pressure operated relay having a second port and being locked insaid off position in response to a particular fluid pressure at saidsecond port;

control means communicating with said pair of manually operated valvesand said second port for applying said particular fluid pressure to saidsecond port a predetermined time delay after operation of either of saidpair of manually operated valves whereby said pressure operated relay islocked in said 011 position; and

feedback means communicating with the outlet port of said pressureoperated relay and said control means and cooperating with said controlmeans to block the application of said particular fluid pressure to saidsecond port in response to fluid pressure at said outlet port wherebysaid feedback means assures actuation of said fluid motor in response tooperation of both of said pair of manually operated valves Within saidpredetermined time delay.

2. The invention as recited in claim 1 wherein said control meansincludes valving means communicating with said pair of manually operatedvalves and said feedback means, and time delay means communicating withsaid valving means and said second port for applying said particularfluid pressure to said second port said predetermined time delay afterreceipt of pressurized fluid from said valving means.

3. The invention as recited in claim 2 wherein said valving meansincludes a pair of pressure actuated control relays.

4. The invention as recited in claim 3 wherein each one of said pair ofpressure actuated control relays communicates with a respective one ofsaid pair of manually operated valves.

5. The invention as recited in claim 4 wherein each of said pair ofpressure actuated control relays communicates with said time delay meansfor controlling the application of pressurized fluid from a respectiveone of said pair of manually operated valves to said time delay means.

6. The invention as recited in claim 5 wherein one of said pair ofpressure actuated control relays communicates with said time delay meansthrough the other of said pair of pressure actuated control relays.

7. The invention as recited in claim 6 wherein said feedback meanscooperates with said pair of pressure actuated control relays to produceactuation of said one of said pair of pressure actuated control relaysand to preclude actuation of said other of said pair of pressureactuated control relays in response to fluid pressure at said outletport of said pressure operated relay.

8. The invention as recited in claim 5 wherein said time delay meansincludes a flow restrictor, a pressure storage tank, and a one-wayvalve.

9. The invention as recited in claim 8 wherein said one-way valve isconnected across said flow restrictor and communicates with said pair ofpressure actuated control relays and said pressure storage tank.

10. The invention as recited in claim 9 wherein said oneway valve isconnected to selectively by-pass said flow restrictor for releasingstored fluid pressure within said pressure storage tank.

References Cited UNITED STATES PATENTS 3,428,084 2/1969 Carls 9l-424XALLAN D. HERRMAN, Primary Examiner US. 01. X.R. 91-424; l9213lR

